I'm not sure what happened bro, but i guess your subs aren't that interested in your stuff anymore (probably due to the break or something else)
I have about 50 dead subs from my previous stint over a year ago doing totally unrelated content to what I am doing right now. In a month I've only grown about 25 subs but I made sure these people were people who were engaged in my content and I only get 3-5 views a day on a newer video that i do almost zero promotion about and i'm happy with that. I get comments(not just random "oh that's nice!" or "Great video!" but genuine appreciation of my content and genuine questions) within the first 1-3 days of releasing which is nice.
My other videos which have higher appeal because they feed on current trends get more promotion efforts from me and I get engagement on those from non subbed as well. I posted one of them on a forum and there's at least 10 people who replied to my video on the forum. (it was slow for the first few days and then people started replying exponentially)
I guess what i'm trying to say is that numbers don't matter if they're not the kind of subscribers that you want. High quality subs.
Think about what your channel can offer, and once you understand that, look for the people who want to watch your content. (people who are missing what you can offer) They will be happy to engage in your videos.
EDIT: I Just looked at your video and it has over 500+ views i don't think you have anything to worry about lol.
and you have 8 comments (which you didn't reply to) you SHOULD reply to them because it keeps them engaged.